That’s because Taylor has redirected his blog, Backchannel.org, to Quip.com, and he’s listed as the application developer on the site.

“We aren’t releasing anything and aren’t yet talking about what we are working on,” Taylor told us. “I will be happy to talk when we are, though.”

If you go to Quip.com, you’re greeted by a Google login screen which asks for permission to view your email address and manage your contacts. If you click on “Learn more,” the site displays Taylor’s email address.

That’s as far as we got: After you log in, the site redirects you to an error screen informing you that you need an invite from a Quip developer.

We found one more clue: The website’s icon, whose pen-and-paper appearance suggests it has something to do with editing documents.

It makes sense that Taylor and Gibbs would build a site based on Google’s infrastructure tools. Both previously worked at Google, and Gibbs led the creation of Google App Engine, a hosting service for third-party software applications.

Some other random bits we found about Quip:

A registration record for Quip.com suggests the domain name may have changed hands as recently as December 7.

There’s a Twitter account, @quip, which only follows two other people: Taylor and Gibbs. Until we started following it Saturday night, its only other follower was Denis Laprise, an Apple engineering manager.

There used to be an iPad app named Quip. Its makers, Glasshouse Apps, changed its name to Tweetglass in July after receiving a legal threat from a company in Europe. It’s not clear that has anything to do with Taylor and Gibbs’s Quip.